HLA-A, B, C; -DR; -MT, -MB, and SB antigens on unstimulated human endothelial cells

Abstract

Since major histocompatibility complex (MHC) antigens of class II play an important role in organ transplantation, their expression on endothelial cells which are abundant in transplants with vascular blood supply was demonstrated. Analysis was performed with monomorphic and polymorphic monoclonal antibodies employing a microscopic immunofluorescence assay and flow cytometry on unstimulated endothelial cells isolated from umbilical cord veins. No evidence was found for the presence of HLA-DR antigens and determinants associated with MT, MB and SB. MHC class I antigens exhibited reduced expression. These findings were confirmed in respect to alloantigens by the use of conventional cytotoxic tissue typing antisera. MB and SB antigens were present on most cord B lymphocytes, but could only be demonstrated on a subpopulation of monocytes exhibiting a lower antigen density at the cell surface. MT and DR antigens were found on most cord monocytes and B lymphocytes.